284 QUESTIONS. 



docs it produce ? How ? How must the change be made ? On what 

 will the number of rootlets depend ? When is burning useful ? What 

 ashes contain most potash ? The rule ? 412. Use of thorough tillage ? 

 What seems to show this ? The reason ? 413. Value of tillage ? The 

 most important use? When may there be danger of overdoing ? 414. 

 Subs oiling ? Effects ? What may draw up the moisture in loosened 

 earth ? 



CHAPTER XIV. 415. What is requisite for plant growth ? What is 

 understood by the mechanical condition of the soil ? 416. Are soils 

 naturally fitted for cultivation ? 417. What condition of the soil is 

 necessary? 418. What do most soils require? Why do they require 

 this ? What harm does standing water do ? 419. Do all soils require 

 the same preparation ? What are the processes most necessary ? 420. 

 Where is clearing generally required ? 421. To what process is 

 the term clearing applied ? When is it begun ? How is it where the 

 wood is valuable ? How may cleared land be got into pasturage ? To 

 what should steep and inaccessible places be devoted ? 422. What is 

 next to be done? How may stumps and stones be removed ? +423. 

 How may the surface overrun with bushes be cleared ? 424. How may 

 wet lands be improved ? The object of drainage? 425. What effect 

 has stagnant water ? 426. How docs exclusion of the air affect soils ? 

 427. How is drainage effected ? Objection to open drains ? Are 

 they as useful as covered ones ? 428. How are the objections to open 

 drains avoided ? How are underdrains made ? The advantage of 

 tiles ? 429. How must a stone drain be laid ? Is it ever good econo 

 my? 430. How is it with a tile drain? 431. Economy of the tile 

 drain ? 432. What is the pipe tile ? 433. What fall is necessary ? 

 434. What is the sole tile? The objection to it? 435. What is a 

 brush drain? How is it laid? Is it efficient ? 436. What distance 

 apart may drains be laid ? How do stiff and porous soils affect the 

 distance of the drains ? 437. What depth is required ? 438. What is 

 the effect of thorough draining ? How does the air affect the soil ? 

 439. With what is the atmosphere charged ? 440. What effect lias 

 draining on the temperature of the soil? 441. What is the result of 

 increasing the temperature ? 442. How does draining affect the texture 

 of the soil? 443. How is land got ready for planting? 444. What 

 implements are used ? 445. What is the spade ? 446. The implement 

 in most common use ? 447. How does the plough operate on the soil ? 

 448. How should the furrow be turned ? 449. What about the depth ? 

 450. What is the Hli-rt &amp;gt;! bringing up tin- subsoil ? 151. Adv;m: 

 of deep ploughing? 452. Whore is it especially necessary? 453. 



